FIELD OF THE INVENTION
This invention relates to the art of driving structures such as rods, tubes, posts, stakes and the like into the ground and especially deals with a ground rod driver successively clamped along the length of the rod or the like for transmitting impact blows from a driving tool to the rod to minimize bending stress of the rod and to provide convenient, safe operating heights for the driving tool.
Heretofore structures to be driven into the ground such as rods, posts, tubes, stakes and the like were impacted at their top ends by manual or power driven hammers. This created an awkward, difficult, and unsafe operating position, especially with rods of more than a few feet in length. When the top end of the rod was above the shoulder height of the hammer operator, it was necessary for the operator to stand on a platform to have the impact blows delivered to the top end of the rod. Even in operations where the driving tool was suspended from an overhead crane or the like, the impact blows delivered to the top end of the rod would tend to bend the rod between the ground and the impacted top end. This type of known driving operation is especially troublesome with long drive rods that force ground anchors into the ground to depths sufficient to fix the anchor in the ground.
In the parent application Ser. No. 509,133 filed Apr. 16, 1990, there is disclosed a ground rod driver which is released from the rod by a manually actuated handle mechanism. This operation requires the operator to release one of his hands from the impacting tool, to stoop over the driver, and to grasp the release handle at ground level while raising the impacting tool with the other hand gripping the tool.
This invention now advances the art by providing an impact tool driven rod clamp which is both locked onto and released from the rod by the tool. It would therefore be a further improvement in this art to automatically clamp, drive, release, raise and reclamp an impact tool driven ground rod driver on a rod without requiring the operator to stoop over or release one of his hands from the impact tool.
It would be a further specific improvement in this art to provide a clamping mechanism for a ground rod driver which retains a clamping jaw on a resilient support that maintains the clamping mechanism in snug but sliding engagement with the rod and is deformed under clamping load to lock the clamping mechanism on the rod.
An important feature of this invention is the provision of a striking block on an impact tool to lock a clamp mechanism of a rod driver on a rod and to provide release blocks on the driver to be imparted by the striking block to unlock the clamp from the rod.